The present invention provides butenoyl and butanoyl cyclohexane and cyclohexene compounds defined by the generic structure: ##STR5## wherein in the cyclohexyl group one of the dashed lines is a double bond and the other two dashed lines are single bonds or each of the three dashed lines are single bonds; in the butanoyl side chain, the dashed line is a single bond or a double bond and wherein one of R.sub.1 or R.sub.2 is methyl and the other of R.sub.1 or R.sub.2 is hydrogen. These compounds are prepared by a straightforward economical process also covered by this invention, which process involves the treatment with hydrogen of a compound having the generic structure: ##STR6## wherein one of the dashed lines or both of the dashed lines are carbon-carbon double bonds and wherein one of R.sub.1 or R.sub.2 is hydrogen and the other of R.sub.1 or R.sub.2 is methyl. The compounds are prepared by means of the following reaction sequence: ##STR7## wherein the cyclohexyl moiety of structure (II) contains a maximum of two double bonds only when the cyclohexyl moiety of structure (I) contains two double bonds.
The present invention also provides for the utilization of the compounds produced by our invention and mixtures produced by the process of our invention which contain the compounds having the chemical structures: ##STR8## or defined by the generic structure: ##STR9## wherein R.sub.1, R.sub.2 and the dashed lines are as above defined, for their organoleptic properties in perfumes, perfumed articles, foodstuffs, foodstuff flavoring compositions, chewing gums, toothpastes, medicinal products, tobaccos, tobacco flavoring compositions, substitute tobaccos and substitute tobacco flavoring compositions.
In the perfumery art there is considerable need for constituents having floral, rose-like, sweet, dry fruity, tobacco-like aromas with heavy fruity (berry), hay-like and slightly camphoraceous undertones. Sweet, full ripe raspberry-like, fruity, grape juice-like, apple juice-like, dried-fruit-like damascenone-like, floral, woody, aroma and flavor characteristics are desirable in many fruit flavors, particularly raspberry flavors, tangerine flavors, grape flavors and apple flavors. Wheat, fruity, hay-like, minty/spicey and woody aromas both prior to and on smoking in the mainstream and in the sidestream are desirable in smoking tobacco flavoring compositions and substitute smoking tobacco flavoring compositions.
Specifically described herein are materials having such an organoleptic profile but which do not discolor with age. Such materials have a wide utilization in the presence of perfume compounds and in foodstuff flavor and tobacco flavoring compounds. A limited amount of such materials that give rise to one or more of these properties individually, is available from natural sources but the natural materials are subject to wide variations in quality, are expensive and are often in critically short supply.
In addition, there is a continuing search for flavor compositions which can vary, fortify, modify, enhance, augment or otherwise improve the flavor and/or aroma of foodstuffs, medicinal products, toothpastes and chewing gums. To be satisfactory, such compositions should be stable, non-toxic and blendable with other ingredients to provide their own unique flavor and aroma nuances without detracting from the contributions of the co-ingredients. Preferably such compositions should be naturally occurring or present in natural foodstuffs so that their ingestible safety can be readily recognized. These materials should be capable of being synthesized in a simple and economical manner. The need for safe flavors in the berry fruit flavor area, especially the raspberry area, the grape flavor area and the apple flavor area is well known particularly in the fruit juice, ice cream and yogurt flavor areas. More specifically, there is a need for the development of non-toxic materials which can replace natural materials not readily available having sweet, full ripe, raspberry-like, fruity, grape juice-like, apple juice-like, dried-fruit-like, floral and woody aroma and flavor characteristics.
The instant invention provides the foregoing which the prior art has heretofore failed to provide. Furthermore, nothing in the prior art shows the unexpected, unobvious and advantageous value of carrying out a hydrogenation process on compounds having the generic structure: ##STR10## wherein at least one of the dashed lines of structure (I) is a carbon-carbon double bond and the other of the dashed lines is a carbon-carbon single bond and one of R.sub.1 or R.sub.2 is hydrogen and the other of R.sub.1 or R.sub.2 is methyl, to provide compounds having the generic structure: ##STR11## wherein at least two of the dashed lines in the cyclohexane moiety of structure II is a carbon-carbon single bond and the other of the dashed lines in the cyclohexane moiety of structure II is either a carbon-carbon single bond or a carbon-carbon bond; and wherein the dashed line is a butanoyl moiety of structure II is a carbon-carbon single bond or a carbon-carbon double bond and one of the moieties R.sub.1 or R.sub.2 is hydrogen and the other of the moieties R.sub.1 or R.sub.2 is methyl.
Described in a prior art are mixtures presumed to be predominantly cis,trans-delta-damascone with minor amounts of trans,trans-delta-damascone (Ayyar, Cookson and Kagi, J. Chem. Soc., Perkin Trans. 1, 1975 (17) 1727-36 [title: "Synthesis of Delta-Damascone [trans-1-(2,6,6-trimethylcyclohex-3-enyl)but-2-en-lone] and Beta-Damascenone [trans-1-(2,6,6-trimethylcyclohexa-1,3-dienyl)but-2-en-1-one]"]. The reaction sequence of the Ayyar synthesis, however, does not concern the step of hydrogenation and is as follows: ##STR12## wherein the wavy line is representative of a "cis" or "trans" configuration of the methyl moiety with respect to the acetyl or crotonoyl moiety, both of which are bonded to the cyclohexenyl moiety, the "cis" isomer presumably being the major isomer and the "trans" isomer presumably being the minor isomer in this reaction sequence.
In U.S. Pat. No. 3,956,392 at column 7 and 8 it is indicated that trans,e-1-crotonyl-2,2,6-trimethylcyclohexane (totally saturated insofar as the ring moiety is concerned) has unexpected, unobvious properties over cis,e-1-crotonyl-2,2,6-trimethylcyclohexane; e-beta-damascenone and e-beta-damascone. The properties of the compound of U.S. Pat. No. 3,956,392 are different in kind rather than degree from the organoleptic properties of the mixtures produced according to the hydrogenation processes of our invention.
Swiss Pat. No. 537,352 issued on July 13, 1973 discloses 1(2-butenoyl)cyclohexenes having the structure: ##STR13## (wherein R may be hydrogen) and this Swiss Patent is abstracted in Chem. Abstracts 79:104808s.
The article, "Structure et synthese de la damascenone (trimethyl-2,6,6-trans-crotonoyl-1-cyclohexadiene-1,3), constituant odorant de l'essence de rose bulgare (Rosa damascena Mill.)" by E. Demole, P. Enggist, U. Sauberli and M. Stoll (referred to herein as Demole, et. al.) discloses the presence of 2,6,6-trimethyl-1(trans-crotonyl)1,3-cyclohexadiene as an "odorous constituent of Bulgarian rose oil". In addition, the Demole et. al. article discloses that dihydro-alpha-damascone results from the "catalytic hydrogenation" of "dehydro-alpha-damascone" produced via "dehydro-iso-ionol". On page 550 of the Demole article, 1,5,5(trimethylbutyne-2-oyl)-6-cyclohexene is indicated to be treated with a Lindlar catalyst of the type used in the instant case thereby producing a mixture containing 4:1 (mole ratio) of alpha-cis-damascone and dihydro-alpha-damascone. The use of such Lindlar catalyst as is set forth in the Demole et. al. reference is well known in the art as is seen in Canadian Patent No. 1,022,187 wherein citral, 3,7-dimethyl-2,6-octadienal is converted to citronellal with yields in excess of 95% by the use of a palladium catalyst and hydrogen gas in an alkaline alcoholic reaction medium. It is indicated that the palladium can be used in any form in Canadian Patent No. 1,022,187 but prefereably that the palladium is supported on a "suitable inert carrier such as charcoal, alumina, barium carbonate, aluminum sulfate, carbon or silica gel".
Nothing in Canadian Patent No. 1,022,187 or in the Demole et. al. article implied that the catalyst of the instant case can be used in such a manner in conjunction with the hydrogenation of compounds having the generic structure: ##STR14## wherein the dashed lines and R.sub.1 and R.sub.2 are as defined above, whereby compounds having the generic structure: ##STR15## in admixture in the proportions indicated can be produced.
In addition, none of the foregoing references discloses the treatment with hydrogen of any one of the genus of compounds having the structure: ##STR16## wherein at least one of the dashed lines is a carbon-carbon double bond and the other of the dashed lines is a carbon-carbon single bond and wherein one of R.sub.1 or R.sub.2 is hydrogen and the other of R.sub.1 or R.sub.2 is methyl.